96 z28 and after I drive it for a while I will be at a stop light and my car will just lose power and die. (I have an aftermarket fuel pump which is very loud, but it gets even louder right before it dies then my car shuts off) the car won't start at first, but if I wait it'll drive around etc but die again if I stop at a light. I'm thinking maybe the iac, vacuum leak, or something? Really need help!

 

do you have any codes? check your fuel pressure.

 

A fuel pump shouldn't be "loud" and then louder. You may have a cheap/defective pump that's giving out, or something may be making it work way too hard. Think possible restriction, like clogged fuel filter perhaps.
Here's an off the wall thought, any chance you might have bent the float arm when you changed the pump, and now your gas tank is almost empty but the gauge isn't telling you that?

 

The previous owner handed me a reciept that said he just had replaced the fuel pump etc (I bought the car with a blown engine) what about the fuel pressuse regulator? And I thought the same, but I put four more gals in it but it still did the same

My engine is only codeing for a sensor for the crankshaft.

I let the car sit for an hour and a half and just drove it 40miles with 0issues. Doesn't make sense! Haha

 

Also I heard all aftermarket fuel pumps were load, is that not true?

 

Loud*

 

not true the granatelli i have in mine is quite.

 

Okie dokie, well I'm changing the pressure regulator and fuel filter so we'll see

 

And theenn

 

You must have a certified, and notarized need to know document in order to find out. lol